Carriage tension release mechanism



Feb. 3, 1959 C. H. BEIDERBECKE CARRIAGE TENSION RELEASE MECHANISM Filed Oct. 20, 1954 IN V EN TOR.

CHARLES H. BEIDERBECKE llma ATTORNEY *CGE TENSION RELEASE MECHANISM Charles H. Beiderheclre, Poughkeepsie, N. Y., assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application October 20, 1954, Serial No. 463,391

4 Claims. (Cl. 19762) This invention relates to typewriters and more particularly to a mechanism for selectively releasing from the carriage, the usual tensioning device or carriage drive mechanism, which is employed to move the carriage across a printing position.

In some typewriter installations, for example, when a typewriter is used for printing music, it is desirable to disengage the carriage drive so that the carriage may be moved freely to any position. Accordingly, it is a first object of this invention to provide a mechanism for selectively disengaging the carriage drive mechanism from the carriage.

A carriage is regulated in its movement by a pawl and rack mechanism whereby the pawl is manipulated to permit the rack to step tooth by tooth across a print position. If the carriage is to be freely movable then it is necessary to disengage the pawl from the rack. In the usual typewriter installation, a release bail is positioned to engage the escapement mechanism and thereby releases the pawl from the carriage so that the carriage may be moved across a print position without the limiting mo tion imposed by the pawl. Therefore, it is a further object of this invention to provide a carriage tension release mechanism which simultaneously operates the carriage release bail to disengage the pawl from the carriage rack.

In dealing with carriage release problems, it should be understood that in conventional power driven typewriters, a carriage return operation is brought about under control of a mechanism, which when actuated energizes a clutch that exerts a pull on the carriage to return it to the left hand margin position. Ideally, it is desirable to. prevent the operation of the carriage return mechanism when the carriage drive motor has been released from the carriage and accordingly, it is a still further object of this invention to provide an improved carriage tension mechanism, which when operated simultaneously releases the carriage drive mechanism and locks the carriage return mechanism.

A still further object of this invention is to provide an improved carriage release mechanism which simultaneously releases the carriage drive motor, actuates the carriage release bail to disengage the pawl from the rack, and locks the operation of the carriage return mechanism.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawing, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawing:

Fig. 1 is a perspective partially cut away view of portions of the typewriter showing the operating features and principles of this invention.

Briefly, this invention relates to an improved carriage tension release mechanism wherein, by depression of a button on the'typewriter housing, a lever is lifted into engagement with the normal typewriter drive means to hook the same and free it from the carriage. Simultaneously, when the drive means, which is usually a tension tape, has been released, a second mechanism will be actuated to disengage the escapement pawl from the carriage rack by the operation of a carriage release bail, thereby freeing the cariage for movement in either direction. carriage release mechanism acts on a bail which is located under the carriage return key to prevent its operation when the tension has been released from the carriage. l

In the drawing, a typewriter car-riage 2 is pictured as being mounted for axial movement across the usual print position. A tape 4 interconnects the carriage and a conventional spring motor mechanism to urge the carriage to the left, which movement is understood to be under the control of a conventional escapement mechanism. The print position, the spring motor, and the escapement mechanism have not been shown since they are so well understood in the art.

In the illustrated embodiment, the tape 4 is provided with a W-shape d clip or part 6 having one loop 8 normally engageable with a clip rest 10 which is pivotally supported on the carriage by a pivot pin 12. An integral leg 16 of the clip rest 10 is pivotally connected at 14 to an arm 18 which is mounted for movement through i a guide bracket 20 to be engageable with the usual carriage release bail 22 that is operable to release a pawl from the escapement rack. Such a bail 22 is more particularly described in U. S. Patent 2,566,963 assigned to the same assignee as thatof the'present invention. The bail 22 is well known in the art and it is felt that no further explanation of its function is necessary. A spring 24 biases the arm 16 clockwise about its pivot pin 12 and consequently, tends to urge the arm 18 into engagement with bail 22 to push it in the direction of the arrow, which movement would normally disengage the pawl from the escapement rack.

The spring motor acting through the tension tape 4 pulls on the clip rest 10 to rotate the same counterclockwise about its pivot 12, thereby nullifying the effect of spring 24 and preventing the releasing action of bail 22, As soon as the tension tape 4 is released from the clip rest 10, however, the spring 24 takes over, urging the arm 18 outwardly into engagement with the bail 22, and thereby releasing the pawl from the rack.

In order to release the tape 4, a tape arm or part 26 is rigidly secured to a rod 28 supported for axial and pivotal movement in a bracket 30, secured to some portion of the typewriter frame. The rod 28 is held normally at its lower limit, by a spring 32, and the clockwise rotation of rod 28 is limited by a shoulder 34, which, as hereinafter described, is biased into engagement with a stop 36, an integral part of bracket 30.

A mechanism is provided for lifting the tape arm 26 into position for engagement with a lower loop 38 of the clip 6 to hook the tape and release it from the carriage. Specifically, a crank arm 40 is pivotally supported at 42 on an ear 44 of the bracket 30. The crank arm 40 is connected by a link 46 to a carriage tension release button 48 that may be mounted for rocking movement about a pin 50 carried by the typewriter frame near the outer housing.

With this structure, the depression of the carriage tension release button 48, urges the link 46 in the direction shown by the arrow to rotate the crank arm 40 clockwise about its pivot 42, whereupon the tip 54 pushes on the undersu'rface of the tape arm 26 to lift it in opposition to spring 32 thereby positioning notch 55 of the tape arm 26 to be engageable with a lower loop 38 of the clip 6. After the notch 55 has been raised to its engaging position, the carriage can then Patented Feb. 3, 1959 7 Furthermore and simultaneously, the' be mtednto-theleftbeyondihe...point...where ,the .cli

6 hooks the notch 55, whereupon the tape 4 is released from the carriage as the latter is moved further to the left Afterthe clip, hasubeen. hooked onto'rthe arm 26, the tension release button 48 is restored to its original position so that spring. :32 .moves shaft i281 to its lower position andhence the tape arm 26:pulls down the clip 6 so thatthe upper loop 8 cannot engage the clip rest 10 as it movesgaxiallyover. the notch 55.. Under these circumstances withthe tape ,4 released, the release bail 22 is actuated to release -the:escapernent pawl so that the carriage is free-tofloatfromleft to right across a print position.

It has been mentioned that one of the objects of this invention was to prevent;operation ofv the carriage return mechanism upon; release'rof -,the: carriage tension tape. This, is ,accomplishedthrough the, operation .ofa

cam 56 which'is secured to shaft 28 and provided with a link 58 which interconnects it with a bell crank 60,.

in turn pivotally supported on-stud 62. Bell. crank .60 has a lock arm 64 rockable intoand out of engagement with the carriage return key lever 66. When the lock arm 64 has been rotated clockwise from theposition.

shown, it fits under a shoulder 68 of the carriage return key lever 66 and thereby blocks its depression for opera-.

tion of the carriage return mechanism (not shown). Normally, spring 61, which is hooked between .crank 60. and the frontframe of the machine, biases the bell crank '60 and, consequently, the lock'arm 64 to the position shown in the drawing so that the carriage return lever is free to operate. Spring 61, acting through link 58 and cam 56, rotates rod 28. and hence shoulder 34.

into engagement with stop 36.

Operation With the illustrated arrangement of the parts, the depression of the carriage tension button 48 lifts the tape arm 26 for engagement with the clip 6, whereupon the tape 4 may be released from the carriage as the latter is moved to the left thus hooking the lower'loop of clip 6 on the notch 55. Once the tape has been hooked on the notch 55, the carriage release bail 22 is operated to disengage the escapement pawl from the carriage rack and the cam 56 is rotated counterclockwise under the influence of tape 4 to pull on link 58 and thereby rotate the lock arm 64 under the carriage return key lever 66 to prevent its depression. To re-hook the tape on the carriage, the latter is first moved so that clip rest it is to the left, of tape arm 26. Then the carriage tension button 48 is depressed to raise the tape arm into engaging position. Movement of the carriage to the right then hooks the upper loop 8 of clip 6 on the clip rest 14) and further movement to the right disengages the tape from arm 26 to re-establish normal typewriter operation.

While there have been shown and described and and in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the .scope of the following claims.

What is claimed is:

l. in a business machine having a carriage with means biasing the same normally. in one direction across a print position and: having means. selectively operable to engage.

and disengage the. carriage biasing means from said carriage, a carriage return lever, means operable in response.

to the actuation thereof for effecting a carriage return operation, means for preventing a carriage return opera tion whensaidbiasing means has-beenreleased from-said carriage, said carriage return prevention device comprising an arm pivotable into and out of blocking engagement with said carriage return lever, means biasing said arm normally out of engagement with said carriage return lever and means interconnecting'said arm and said carriage biasing means for urging said arm into its lever blocking positionwhile saidcarriagebiasing means has been released from said carriage.

2. In a typewriterhaving a carriage, a clip rest mounted on said carriage, a tension tape engageable with said clip rest for biasing said carriage in one direction across a print position, a device for selectively engaging and disengaging said tape'from said carriage comprising, a tape arm, means mounting the same on the frame of said typewriter for movement into and out of engagement with said tape, spring means biasing said tape arm normally out of engagement from said tape, an operating-switch leverfor said tape :arm, cam means for moving said tapearm -in opposition-t0 said spring biasing means, link means interconnecting saidcam means and-said tape arm switch lever for actuating said canrmeans to move said tape:arm into engagement with saidtensionatape, clip means on-said tape for-engaging both said carriage and said-tape :arm when the latter has been moved-to its tape engaging position whereby said tape may be disengaged from said carriage by moving the same in its tape biased direction after'said tape arm-has been moved toits tape engaging position, said carriage having a carriage. release bail, spring :biased means interconnecting said clip rest andsaid carriage release bail tobias the latter to its carriage release position, said tape. disabling said spring biased means when said tape clip engages said carriage clip rest, a key lever for operating the typewriter carriage return mechanism,'a rockable arm mounted on said typewriter frame for movement into and out of locking engagement with saidkey. lever to prevent its operation,

and link means interconnecting said rockable arm and said tape arm mounting means for moving said rockable arm into a position tobloclcsaid key lever when said.

tape armhas released said tension tape from said carriage.

3..A business machine .having in combination a carriage, selectively 'engageable means for tensioning said carriage vacross 'a printposition, a carriage release device having a carriage .releaseposition, means tensioning the same normally to its carriage release position, and means disabling. said carriage release tensioning devicewhile said carriagetensioning means is engaged.

4. In a *businessmachine having a carriage, a clip rest mounted. on said carriage, means engageablewith said clip rest forv biasing said carriage for movement in one direction across a print position, a device for selectively engaging :and disengaging said engageable means from said carriage. clip rest, a carriage release bail, means'opere able by said carriage clip rest for actuating said bail, meansoperating on said carriage clip rest and urging said bail actuating. means normally into engagement with said carriage release bail to move the latter to its carriage release position,-said operating means being counteracted when said'engageable means is in engagement with said clip rest and effective when said engageable means has been released from said carriage clip rest whereby said carriage release bail is moved to its carriage release position.

References Cited in the file of this patent UNITED STATES PATENTS 1,120,391 Knapp Dec. 8, 1914 FOREIGN PATENTS Great Britain Sept. 16, 1942 

